Cryo-EM reveals distinct conformations of E. coli ATP synthase on exposure to ATP.

ABSTRACT: ATP synthase produces the majority of cellular energy in most cells. We have previously reported cryo-EM maps of autoinhibited E. coli ATP synthase imaged without addition of nucleotide (Sobti et al. 2016), indicating that the subunit ? engages the ?, ? and ? subunits to lock the enzyme and prevent functional rotation. Here we present multiple cryo-EM reconstructions of the enzyme frozen after the addition of MgATP to identify the changes that occur when this ? inhibition is removed. The maps generated show that, after exposure to MgATP, E. coli ATP synthase adopts a different conformation with a catalytic subunit changing conformation substantially and the ? C-terminal domain transitioning via an intermediate 'half-up' state to a condensed 'down' state. This work provides direct evidence for unique conformational states that occur in E. coli ATP synthase when ATP binding prevents the ? C-terminal domain from entering the inhibitory 'up' state.

SUBMITTER: Sobti M 

PROVIDER: S-EPMC6449082 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature